package linkedlistmapcode;

import bstsetcode.FileOperation;

import java.util.ArrayList;

/**
 * @author noob
 * @version 1.0
 * @date 2021/3/18 12:30
 */
public class LinkedListMap<K,V> implements Map<K,V> {

    private class Node{
        private   K key;
        private   V value;
        private Node next;

        public Node(K key, V value, Node next) {
            this.key = key;
            this.value = value;
            this.next  =next;
        }

        public Node(K  key){
            this(key,null,null);
        }

        public Node() {
            this(null,null,null);
        }

        @Override
        public String toString() {
            return key.toString() +":"+ value.toString();
        }
    }



    private Node dummyHead;
    private  int size;

    public LinkedListMap(){
        dummyHead = new Node();
        size = 0;
    }

    /**
     * 辅助函数--获取结点
     * @param key
     * @return
     */
    private Node getNode(K key){
        Node cur = dummyHead.next;
        while (cur !=null){
            if(cur.key.equals(key)){
                return cur;
            }
            cur = cur.next;
        }
        return null;
    }

    @Override
    public void add(K key, V value) {
        /**
         * 先判断key存不存在
         */
        Node node = getNode(key);
        if(node == null){
            dummyHead.next = new Node(key,value,dummyHead.next);
            size++;
        }else{
            //覆盖原值--设计问题
            node.value=value;
        }
    }

    @Override
    public V remove(K key) {
        Node prev = dummyHead;
        while (prev.next !=null){
            if(prev.next.key.equals(key)){
                break;
            }
            prev = prev.next;
        }
        if(prev.next != null){
            Node delNode = prev.next;
            prev.next=delNode.next;
            delNode.next=null;
            size--;
            return delNode.value;
        }
        return null;
    }

    @Override
    public boolean contains(K key) {
        return getNode(key) !=null;
    }

    @Override
    public V get(K key) {
        Node node = getNode(key);
        return node == null? null:node.value;
    }

    @Override
    public void set(K key, V newValue) {
        Node node =getNode(key);
        if(node == null){
            throw  new IllegalArgumentException(key + " doesn't exists");
        }
        node.value=newValue;
    }

    @Override
    public int getSize() {
        return size;
    }

    @Override
    public boolean isEmpty() {
        return size==0;
    }


    public static void main(String[] args) {

        System.out.println("Pride and Prejudice");

        ArrayList<String> words = new ArrayList<>();
        if(FileOperation.readFile("pride-and-prejudice.txt", words)) {
            System.out.println("Total words: " + words.size());

            LinkedListMap<String, Integer> map = new LinkedListMap<>();
            for (String word : words) {
                if (map.contains(word))
                    map.set(word, map.get(word) + 1);
                else
                    map.add(word, 1);
            }

            System.out.println("Total different words: " + map.getSize());
            System.out.println("Frequency of PRIDE: " + map.get("pride"));
            System.out.println("Frequency of PREJUDICE: " + map.get("prejudice"));
        }

        System.out.println();

    }
}
